Electricity Overview Quiz

Study Notes

The flow of electrons in a closed circuit that allows work to be done.
Plays a significant role in daily life for lighting, heating, cooling, entertainment (TV and radio), transportation, and calculations.
Every matter is electrical in nature due to the presence of charged particles like electrons and protons.
A body is typically neutral as it contains an equal number of protons and electrons.
If electrons are removed from a body, it becomes positively charged due to an electron deficit.
If electrons are supplied to a body, it becomes negatively charged due to an excess of electrons.
The unit of charge is the coulomb (C).
One Coulomb is the charge on 6.28 x 10¹⁸ electrons.

Electrons loosely attached to the nucleus of an atom, able to move when external energy is applied.

The capacity of a charged body to perform work.
Measured in volts (V) or joules per coulomb (J/C).
A body has an electrical potential of 1 Volt if 1 Joule of work is done to charge the body to 1 Coulomb.

The continuous flow of electrons in an electric circuit, driven by an applied potential difference.
The rate of flow of electrons, or charge flowing per second.
Calculated using the formula: I = Q / t, where:
- I = current (Amperes)
- Q = charge (Coulombs)
- t = time (seconds)

The amount of energy used by one Coulomb of charge when moving from one point to another in a circuit.

States that the current through a conductor is directly proportional to the applied voltage across it, assuming constant physical conditions like temperature.
The proportionality constant is known as the resistance 'R' of the conductor.
Measured in ohms (Ω).
Mathematically represented by: R = V / I
The voltage drop across a resistor is calculated as V = IR, meaning the potential difference across the resistor is equal to the current flowing through it multiplied by the resistance.

Not applicable for unilateral networks (e.g., diodes, transistors) that allow current flow in only one direction.
Not applicable to non-linear networks, where the relationship between voltage and current is not linear.